Oxygen regulating system



3, 1954 G. c. FIELDS ETAL 2,685,288

OXYGEN REGULATING SYSTEM Filed Nov. 17. 1949 2 Sheets-Sheet l GEoRaE C.FIELDS THOMAS HREDDNGTON INVENTOR.

WWW 6444M ATTORNEY 3, 1954 G. c. FIELDS ETAL 2,685,288 OXYGEN REGULATINGSYSTEM Fi'led Nov. 17. 1949 2 Sheets-Sheet 2 a! a7 1; Z l7 53.3 I5 I63l9 5 R3 as I I i I I I ,1 I I5 -14 s PERCENT OXYGEN 8 PRESSURE 1 \NCHESH O woZ- 6 5 7570-- 4 OXYGEN 3 c a I I CAM 252 1 o GEORGEC-FIELDS. D A B5 THOMASHREDDMGTON l 1 I I o 5 l0 :5 a0 2530354045 50 560 THOUSAND FEETBYWfl- W HTTORNEY F\ 4 Patented Aug. 3, 1954 QXYGEN- BEGULATING S S EMGeorge 0. Fields, Wilmette, and Thomas Redsaid: Bxeddingtcn assignordingt n, ChiQa si-,.I. l.-; to- Johnson Fare Box m any, Chicago, l.

a corporation of Delaware, Application November-- 17, 194 9; Serial No.127,834

13 Claims 1 This invention relates to oxygen regulators. Morespecifically, it relates. to anoxygen regus later which is pressurecompensating and is. particularly intended for high altitude flying.

It is an object of the invention to. provide. anoxygen regulator systemwhich is: capable. of; ieeding varying amounts of oxygen and air to. thewearer of an oxygen mask, the amount of, oxygen increasing as the.altitude increases until at a predetermined altitude pure oxygen issupplied and at a, different pre eterminedalti ude oxygen is maintainedvat a positive pressure in said mask.

A fur her jectv s t prov an oxy en re allater and mask in which theamount of positive or a v pre s r r quired to e exerted by the. w r r tpe a the s stem. never xceed one inch of water at any altitude.

t a oth r o ject of the invent on is to pr vide a regulator system whichis fully automatic and which qu res no manua ad ustments what.- everthroughout the entire. range of its opera-. tion.

Another object of the invention is to provide a regulator system whichis positive in open yet relatively simple.

Yet a further object of the invention is to: pro-v vide a mechanismwhich will conserve the oxygen supply.

It is another object of the invention to provide a system which can beoperated with a minimum of exertion by the wearer.

Still another object is to provide a system which will operateautomatically toadjust the oxygen supply as the altitude down.

A further object is to provide a system which will supply oxygen insubstantial accordance with present aeromedical standards.

These and other objects of the invention will become apparent from astudy of this specification and th drawings which are attached here to,are made a part hereof and in which: I

Figure 1 is a vertical sectional view of a portion of the system showingthe oxygen valve, the exhaust valve, the diaphragms for operating themand also the aneroid for automatically regulating the supply of oxygen.

Figure 2 is a vertical sectional View 01 the mask showing the air inletcontrol valve the exhaust control and the oxygen inlet.

Figure 3 is a sectional view takensubstantially on line 33 of Figure 1showingthe control cam and its mounting.

changes up and Figure 4 is. a graph showing generally the operation ofthe system.

Structure Referring first to Figure 2, the numeral 1 repr sen a fac maskf any itabl g s-ti ht mate ial, which is, provid d wit a fi n 3 hav ihan a r inlet ort tiwhieh ommunicates with th at osph re on the utside fh mask a d open into a. h m er 1 h vin p ts 3 commumeeting w th th in ei r o th ma The hamb r is. def n d in. part b the fit n and in part bythe diaphragm or valve operator H i h. he d. n ace on .3 by the. case.1?..-

The d ap a m is. r de cent al y n. one si h n. nward1 -0penin al whichon o s. e It carries as rin s at l1 e ia ly he sid o osite he. val

A ompres on. s z hg fl. re ts he at i hd a r e 1 n. c s I d normal y u sva -5 0 clo e r 5- The diaphr m a so ae at s h valve s. escr bed b lowThe a e i s r de ith. a ma l bleeder 23 hich. r es as a vent tor chamb r.5 between the diaphragm II and case l3. The chamber- 25 a d a r gm IIare hereihai referr d o as he val actuator r th ak Q brev yi e e is eably bou 1 inch in diameter and communicates with the inte ior o e.mask- A- metal or conduit m ihica s. with ham e 25am t r n te a h se 2:which sea g y pass d. t ro h th w l i the. ma k- An oxy en sup hos 3ttac ed tea fi i 3 fix o hewall f the mask and a p o control hos isattached to t e. w ll oi the mask- Both hoses communig te w e interior ot e mask- It should be note that there is considerable area of the dihra m H and valve 5 exposed n ham er Reierring now to Figure 1, theoxygen hose 3|. is attached tea b ss 39 on the regulator body M. Theconduit 43. through the boss. communie cates with oxygen supply chamberwhich is u plied wi h. xy n und r ab ut 20. p. sia elute thr u h i le 1and screen. is and constitutes means di h g g oxy en fr m the p ly i qhe ho e C ndui s clos d y ownwardly actin poppet-type valve 49 which isurged toward closed position by spring 5|. The valve is pivotallysupported at 53 on a lever 55 which is pivoted at. one end. at 51. Theother end of the lever is pivotally connected to a stem 59 which is 3mounted centrally in a diaphragm 6| which forms one wall of chamber 45.

A control chamber 63 is formed in the body 4| above the diaphragm andcommunication is had between this chamber and chamber 45 through thesmall bleeder port 65, preferably having a diameter of .006, formed inthe grommet 61 fixed in the diaphragm.

The hose 35 is attached to a boss 69 on the body 4| and communicates byway of conduit II with a demand chamber 13 which in turn communicateswith chamber 63 through a port I5 which is controlled by a needle valveTI.

A Y-shaped plate 19 straddles the port I5 and is held in place by screws8|. A pair of ears 83 rise from the plate and a lever 85 is pivoted atone end on the ears. The lever carries the needle valve 11. A screw Illis screwed in the plate, rides in a hole 89 in the body and serves toadjust the valve relative to the seat.

The free end of lever 85 is pivotally connected to post 9| which isfixed to the central portion of a diaphragm 93. The chamber 05 above thediaphragm communicates with chamber I3 through port 9? which also passespost 9|.

The chamber 99 on the other side of the diaphragm is open to atmosphereand contains a lever IOI which has one end pivoted at I03 to a bracketI05 fixed to body 4|. The other end of the lever has a screw I| threadedtherein which bears against the center portion of the diaphragm 03. Alook nut I09 holds the screw in its adjusted position.

A compression spring III under sea level conditions has its upper enddisposed adjacent the bottom side of the free end of the lever but outof contact therewith and has its other end resting upon the spring seatH3. The seat has a recess II formed to receive the spring and has acentral plunger Ill which rides in a bushing I I9 fixed in the lowerwall I2| of the chamber 99.

The under side of lever IOI adjacent the pivot I03 bears on a thrust pinI23 mounted for reciprocation in guide I25 formed integral with bracketI05.- Hose 29 is fixed to a boss I2'| which has a channel I29communicating with exhaust chamber I3 I. The latter chamber communicatesthrough port I33 with chamber 99.

A downwardly facing valve seat I35 is positioned adjacent the port I33and is closed by the vertically reciprocating control valve I3'I whichis normally urged into contact with the seat by spring I39. The thrustpin I23 engages the valve to open it when lever IN and pin I23 aredepressed.

An aneroid housing MI is attached to the body 4| and is vented at I43 toatmosphere. A sealed aneroid bellows I45 is mounted in the housing.

Bracket I41 mounted on the housing has pivotally mounted thereon at I49a cam |5I which is pivotally connected by a slot I53 to a pin I55 fixedto the free end of the bellows. The cam has three rises A, B and C andtwo dwell or rest portions D and E.

A U-shaped cam follower lever I5! is pivotally mounted at I59 on bracketI41, carries a follower roll IBI in ball or other anti-friction bearingsI63. The bar portion I65 of the lever I57 is extended to engage theplunger II! of spring seat II3.

Operation The system described above is intended to supply a'man at allaltitudes from sea level to 50,000

Gil

4 feet with the proper breathing atmosphere td enable him to workefiiciently while, at the same time, conserving the supply of oxygen.

The chart, Figure 4, explains the approximate operation of theregulator. The rises and dwells or rests of the cam I5I are shown in thelowermost curve. Dwell D is effective until approximately 15,000 feet;rise A extends to about 25,000 feet; rise B to 30,000 feet; rest E to40,000 feet and rise C through and beyond 50,000 feet.

The oxygen percentage curve is a straight-line, altitude curve until therise A is reached, whereupon the rate of rise increases as a function ofaltitude and the rise A. When rise B is reached, the slope of the curveincreases at a rate which is a function of altitude and the rise B. Thiscurve is followed until one hundred per cent oxygen is fed, which occursat or prior to approximately 30,000 feet at which point the curve levelsoff.

The remaining curve represents the static or mean pressure in the maskin inches of water. No attempt is made to show the fluctuations due tobreathing. It should be understood, however, that such fluctuations willnever exceed one inch of water pressure above or below this curve, asshown by the dashed lines on either side of the curve.

The rise B is effective to increase the oxygen supply between 25,000 and30,000 feet so that at the latter altitude the mean pressure levels 01fat one inch of water and continues at this figure by reason of rest Euntil at 40,000 feet rise C becomes effective. The rise in pressure isrelatively rapid and reaches 14 inches at 50,000. The rate of risecontinues for altitudes beyond this but, of course, few operations arecarried out above this level.

Thus the regulator supplies an increasingly enriched air supply up toapproximately 30,000 feet after which it supplies all oxygen, at apositive pressure of one inch, up to 40,000 feet. Thereafter thepressure increases at a rate which will produce 14 inches at 50,000feet. The inhalation pressure is never more than one inch and theexhalation pressure is never more than one inch above mean mask pressurethroughout the entire range.

Sea level Referring first to the operation of the device at sea level,it will be seen that the aneroid bellows will occupy their smallestcompressed position so that the rest D of cam |5I will be effective andspring seat II3 will occupy its lowest position.

The lever IOI is preferably out of effective contact with diaphragm 93under these conditions except on the exhalation cycle when the lever isoperated by the diaphragm.

On the inhalation cycle person wearing the mask will, upon inhaling,slightly reduce the pressure within the mask. This reduced pressure isapplied through bleeder 23 to chamber 25 and through ports 9 tochamber 1. However, since the pressure in port 5 is about 14.7 p. s. i.,the reduction in pressure in the mask will need be very small,substantially only enough to overcome spring I9 which constitutes afixed load, before the valve I5 is pushed open and the requirement forair will be satisfied.

Upon exhalation, the pressure in the mask is slightly higher than thatin the port 5. The pressure is applied to chambers and 25 and spring I9overcomes the slight unbalance tending 5, to open the valve and seatsvalve [5. Themessure mthe mask is then applied through tube 3'5 todiaphragm 93 which depresses lever HH and pinl23 to open valve I31.

The air under pressure in chamber 25 is then. passed from the chamberthrough hose 29', chamber I31, valve i3! toatmosphere. The consequentreduction of the pressure within chamber 25*to substantially atmosphericpressure permits the super atmospheric pressure in chamber 1 combinedwith the atmospheric pressure in port 5 to overcome spring 10, the valveopens and the exhalation is passed out through port 5.

Sea level to 15,000 feet As the altitude increases progressively, theatmospheric pressure exerted in port 5 becomes less and less so that asthe wearer of the mask continues to inhale normally, the valve l5 willopen to a progressively less degree while valve 11 opens correspondinglyto a greater degree because the suction created upon inhalation, being,unsatisfied through port 5, is applied to greater degree to diaphragm 93which opens valve T! which supplies the deficiency by relieving pressurein chamber 63 more quickly than it can be balanced through port 05 fromchamber 45.

Diaphragm 6i accordingly rises and opens valve 09 and permits oxygen toflow from chamber 45 through tube 3i into the mask to satisfy thedemand. Oxygen is thus fed in increasing proportion as shown in Figure4.

15,000 to 25,000 feet The aneroid I45 has at the altitude of 15,000 feetor thereabout, moved the rise A on cam IM to the position where it willpick up the follower and a further increase in altitude will raiseplunger Ill and start to raise the lever ll so that it will begin toassume the weight of the parts which are supported by the diaphragm 93.This will make the upward travel of diaphragm 93 easier with the resultthat valve Tl, which has heretofore opened in direct ratio with thedecrease in atmospheric pressure, will now open to a greater degree thanthat which would be induced by the decrease in atmospheric pressure. Theoxygen curve (Fig. 4) accordingly has a slope which increases at a rategreater than the rate of change of altitude.

25,000 to 40,000 feet After the cam rise A has raised the follower I51,the rise B is reached. Thus the rate of upward adjustment of lever Hllis increased for a period corresponding to the altitudes from 25,000 to30,000 feet. The rate of increase in the percentage of oxygen is againaccelerated. Somewhere at or before the latter altitude is reached, theregulator will be supplying 100% oxygen because upon inhalation thevalve 11 is opened to a greater degree than heretofore and, since thereis now very little pressure in port 5, the valve I does not open at all.By the time the end of rise B is reached and rest E is engaged, the meanor static mask pressure will be held at one inch of water. Thiscondition. is maintained until the final rise C is reached at 40,000feet.

40,000 to 50,000 feet and over When the aneroid reaches the 40,000 footposition, the step C of the cam contacts the follower. The step is longenough so that it imparts a regular rise to the follower from the 40,000

6, foot position to the 50 ,000.- foot position. and. beyond.

As the spring H1 is raised progressively by the cam follower, it moveslever- I01 diaphragm 93 and valve 1! tosucha position that oxygen willbe fed to the mask at rates sur'fi'ci'ent to increase the oxygenpressure inthe mask pro-- portionately withincrease in altitude so thatat 50,000- feet the static pressure is 14 inches of water.

Constant exhalation pressure It is desired thatthe amount of pressurewhich the wearer need exert to exhale be maintained at or below one.inch of water pressure in excess of the mean or static pressure in themask.

In order to attain this goal, the spring llll which is raised by theaneroid as thealtitude increases, is so designed that it does not.require pressure of more than one inch of water applied to diaphragm 03vto compress the spring far enough to open valve I31, irrespective of theposition of the cam.

The exhalation is effected at each of the vari-' ous. altitudes inexactly the same. manner as described in the last paragraph of thesection of the specification entitled Sea Level.

As the altitude decreases, the steps and functions described above occurin the reverse order under the. control of the aneroid and the changesin atmospheric pressure.

It is obvious that various changes may be made in the form, structureand arrangement of parts without departing from the spirit. of theinvention. Accordingly, we do not desire to be limited to the specificembodiment disclosed herein primarily for purposes of illustration; butinstead, we desire protection falling fairly within the scope of theappended claims.

What we claim to be new and desire to protect by Letters Patent or" theUnited States is:

1. In an oxygen regulating system, a mask, a chamber supported by themask having a diaphragm as one wall, an atmospheric port in the maskadjacent the diaphragm, an inwardly opening valve carried by thediaphragm and movable therewith to open and close the port, means forapplying pressure in the mask to the diaphragm on the side of said port,yieldable means for normally urging the valve closed, a restricted portin said chamber communicating with the mask, a second port in saidchamber normally out of communication. with the atmosphere and meansresponsive to exhalation pressure in the mask for connecting said secondport for communication with the atmosphere to open said first port.

2. In an oxygen regulating system, a mask, a chamber supported by themask having a diaphragm as one wall, a first atmospheric port in themask adjacent the diaphragm, an inwardly opening valve carried by thediaphragm and movable therewith to open and close the port, means forapplyin pressure in the mask to the diaphragm on the side of said port,yieldable means for normally urging the valve closed, a restricted portin said chamber communicating with. the mask, a second port in saidchamber, a second diaphragm, means including a conduit connecting oneside of said second diaphragm in communication with the interior of themask, a channel connecting said second port to atmosphere and a valveconnected for operation by said second diaphragm to open and close saidchannel.

3. In an oxygen regulating system, a mask, a chamber supported by themask having a diaphragm as one wall, a first atmospheric port in themask adjacent the diaphragm, an inwardly opening valve carried by thediaphragm and movable therewith to open and close the port, means forapplying pressure in the mask to the diaphragm on the side of said port,yieldable means for normally urging the valve closed, a restricted portin said chamber communicating with the mask, a second port in saidchamber, a second diaphragm, means including a conduit connecting oneside of said second diaphragm in communication with the interior of themask, a channel connecting said second port to atmosphere and a valveconnected for operation by said second diaphragm, upon operation thereofby exhalation pressure in the mask, to open said channel.

4. In an oxygen regulating system, a mask, a chamber supported by themask having a diaphragm as one wall, a first atmospheric port in themask adjacent the diaphragm, an inwardly opening valve carried by thediaphragm and movable therewith to open and close the port, means forapplying pressure in the mask to the diaphragm on the side of said port,yieldable means for normally urging the valve closed, a restricted portin said chamber communicating with the mask, a second port in saidchamber, a second diaphragm, means including a conduit connecting oneside of said second diaphragm in communication with the interior of themask, a channel connecting said second port to atmosphere, a valveconnected for operation by said second diaphragm, upon exhalation, toopen said channel, an oxygen inlet conduit connected with the mask andincluding a control valve for admitting oxygen to the mask.

5. In an oxygen regulating system, a mask, an oxygen supply chamber anda control chamber separated therefrom by a diaphragm, said diaphragmhaving a restricted opening, an inlet for said supply chamber, an oxygendischarge port in the supply chamber, means connecting said port incommunication with the mask, a valve for the port connected foroperation by the diaphragm, a discharge port in the control chamber, aneedle valve for controlling the port, a demand chamber communicatingwith the mask, a second diaphragm open to said demand chamber on oneside and to atmosphere on the other and means connecting said seconddiaphragm to actuate said needle valve.

6. In an oxygen regulating system, a mask, an oxygen supply chamber anda control chamber separated therefrom by a diaphragm, said diaphragmhaving a restricted opening, an inlet for said supply chamber, an oxygendischarge port in the supply chamber, means connecting said port incommunication with the mask, a valve for the port connected foroperation by the diaphragm, a discharge port in the control chamber, aneedle valve for controlling the port, a demand chamber communicatingwith the mask, a second diaphragm open to said demand chamber on oneside and to atmosphere on the other, means connecting said seconddiaphragm to actuate said needle valve, an aneroid, a cam connected foroperation by said aneroid and means, including yieldable means, fortransmitting pressures from said cam to said second diaphragm in aid ofthe atmospheric pressure.

'7. I h an oxygen regulating system, a mask, an oxygen supply chamberand a control chamber separated therefrom by a diaphragm, said diaphragmhaving a restricted opening, an inlet for said supply chamber, an oxygendischarge port in the supply chamber, means connecting said port incommunication with the mask, a valve for the port connected foroperation by the diaphragm, a discharge port in the control chamber, aneedle valve for controlling the port, a demand chamber communicatingwith the mask, a second diaphragm open to said demand chamber on oneside and to atmosphere on the other, means connecting said seconddiaphragm to actuate said needle valve, an aneroid, a cam connected foroperation by said aneroid, a follower for said cam and a compressionspring connecting said follower with the atmospheric side of said seconddiaphragm.

8. In an oxygen regulating system, a mask, an oxygen supply chamber anda control chamber separated therefrom by a diaphragm, said diaphragmhaving a restricted opening, an inlet for said supply chamber, an oxygendischarge port in the supply chamber, means connecting said port incommunication with the mask, a valve for the port connected foroperation by the diaphragm, a discharge port in the control chamber, aneedle valve for controlling the port, a demand chamber communicatingwith the mask, a second diaphragm open to said demand chamber on oneside and to atmosphere on the other, means connecting said seconddiaphragm to actuate said needle valve on the inhalation portion of thecycle; an exhaust port in said mask, a third diaphragm including a valvefor controlling said port, a control valve adapted to open and close,means communicating with and controlled by said control valve to actuatesaid third diaphragm to open and close the port, and means connectingsaid control valve for operation by said second diaphragm.

9. In an oxygen regulating system, a mask, an oxygen supply chamber anda control chamber separated therefrom by a diaphragm, said diaphragmhaving a restricted opening, an inlet for said supply chamber, an oxygendischarge port in the supply chamber, means connecting said port incommunication with the mask, a valve for the port connected foroperation by the diaphragm, a discharge port in the control chamber, aneedle valve for controlling the port, a demand chamber communicatingwith the mask, a second diaphragm open to said demand chamber on oneside and to atmosphere on the other, means connecting said seconddiaphragm to actuate said needle valve on the inhalation portion of thecycle, an exhaust port in said mask, a third diaphragm including a valvefor controlling said port, a control valve adapted to open and close,means communicating with and controlled by said control valve to actuatesaid third diaphragm, a lever connecting said control valve with saidsecond diaphragm, an aneroid, a cam means operated thereby and a springconfined between said cam means and lever for applying variable pressureto said second diaphragm in aid of said atmospheric pressure.

10. In an oxygen regulating system, a mask, an oxygen supply chamber anda control chamber separated therefrom by a diaphragm, said diaphragmhaving a restricted opening, an inlet for said supply chamber, an oxygendischarge port in the supply chamber, means connecting said port incommunication with the mask, a valve for the port connected foroperation by the diaphragm, a discharge port in the control chamber, aneedle valve for controlling the port, a demand chamber communicatingwith the mask, a second diaphragm open to said demand chamber on oneside and to atmosphere on the other, means connecting said seconddiaphragm to actuate said needle valve on the inhalation portion of thecycle, an atmospheric port in said mask, a third diaphragm adjacentthereto having a valve for controlling the port, first and secondchambers on opposite sides of said third diaphragm, said first chamberbeing adjacent the port and in open communication with the mask, saidsecond chamber having a restricted port to the mask and a control port,a valve disposed to open and close the control port and means connectingsaid valve for operation by said second diaphragm.

11. In an oxygen regulating system, a mask, an oxygen supply chamber anda control chamber separated therefrom by a diaphragm, said diaphragmhaving a restricted opening, an inlet for said supply chamber, an oxygendischarge port in the supply chamber, means connecting said port incommunication with the mask, a valve for the port connected foroperation by the diaphragm, a discharge port in the control chamber, aneedle valve for controlling the port, a demand chamber communicatingwith the mask, a second diaphragm open to said demand chamber on oneside and to atmosphere on the other, means connecting said seconddiaphragm to actuate said needle valve, an atmospheric port in saidmask, a third diaphragm adjacent thereto having a valve for controllingthe port, first and second chambers on opposite sides of said thirddiaphragm, said first chamber being adjacent the port and in opencommunication with the mask, said second chamber having a restrictedport to the mask and a control port, a valve disposed to open and closethe control port, means connecting said valve for operation by saidsecond diaphragm, an aneroid, a cam connected for operation thereby andmeans, including a spring, connected to transmit pressure of said cam tosaid valve operating means and thereby to said second diaphragm in aidof said atmospheric pressure.

12. In an oxygen regulating system, a mask, an atmospheric port in themask, a valve mounted for movement to open and close said port, an

actuator for said valve, means for applying mask pressure to saidactuator to close the valve, a vent for the pressure applying means, avalve to control the vent, exhalation responsive means for opening thevent valve, an aneroid and compressible means for transmitting movementof the aneroid to said responsive means in opposition to exhalationpressure, the area of said responsive means and the yieldability of saidcompressible means serving to open said vent valve, upon application ofa pressure equal to not more than one inch of water in said mask,irrespective of the expanded condition of said aneroid.

13. In an oxygen regulating system, a mask, an atmospheric port therein,a valve for controlling the port, means responsive to exhalationpressure within the mask for opening the valve, said means beingresponsive to inhalation pressure within the mask for opening said valveunder predetermined atmospheric pressure conditions, means disposed tocontrol the operation of said valve opening means for decreasing themagnitude of opening of the valve as the atmospheric pressure decreases,an oxygen inlet conduit connected with said mask and control meansresponsive to inhalation pressure within the mask for admitting oxygenfrom said conduit to the mask, said control means including meansresponsive to decreasing atmospheric pressure for increasing thequantity of oxygen supplied.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 439,093 Borian Oct. 28, 1890 851,830 Park Apr. 30, 1907988,352 Kerr Apr. 4, 1911 1,926,069 Sutton Sept. 12, 1933 2,378,047Strange June 12, 1945 2,384,669 Fields Sept. 11, 1945 2,552,595 SeelerMay 15, 1951 2,608,971 Holmes Sept. 2, 1952 FOREIGN PATENTS NumberCountry Date 478,412 Great Britain Jan. 18, 1938 645,056 Germany May 20,1937

